Subject:
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Re: Probably burned serial interface -- need help
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Newsgroups:
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lugnet.robotics.handyboard
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Date:
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Wed, 23 Jan 2002 20:19:08 GMT
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Viewed:
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2954 times
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Thanks to all who offered help. But I'm afraid I may need some more...
In response to some questions: Yes the pop came from the board, not the
wall-mounted adapter, and yes, I do have a voltmeter. But it hadn't occurred
to me to check the testing instructions on the Handyboard assembly manual (I
bought mine assembled). I downloaded it and went through the steps suggested
and it seems clear there is something wrong.
- First I went though the tests for the power circuit (sec 3.1.2 of the
manual), and everything seems to be fine: I do have exactly 5.0 V across the
terminals of C14, %.) V out of the voltage regulator, etc.
- Then, I went through the next series of tests (sec 3.2.2) for the serial
circuit, and here the troubles began. Between pins 2 and 7 of the IC I have
3.2V (instead of the 9/10 V the manual indicates ) and between pins 6 and 7
I have -0.4 V instead of -9/-10V.
This seems to indicate (acc to the manual) that the troubled capacitors are
one or more of C10-C13.
(I didn't try any other test, as they seem to depend on the correct
functioning of the other parts of the board.)
Could anyone tell me if this inferfence is correct and, furthermore, if
there is anyway to further pinpoint the damage? I could replace all 4 caps,
but I would like to minimize the use of my not exactly superlative soldering
skills.
Thanks,
Stefano
In lugnet.robotics.handyboard, John R. McDaniel writes:
> Stefano,
>
> Do you have a voltmeter?
>
>
> > yesterday I mistakenly plugged the 110V/9V AC adapter that feeds the
> >
> > Stefano Franchi
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